It's interesting to see the relatively small hand-held cameras that they use. I doubt if they use the big crane-mounted cameras at all, except maybe for the high angle shots looking down a street....

In pic [You must be registered and logged in to see this link.] it looks like Lauren has a small camera mounted on the end of her gun barrel to get a close up of the walkers throat as she "kills" it. I can't tell for sure but it looks like the rifle is an old model used by the Russian army as far back as the 19th Century. Those are readily available on the surplus market at very low prices so it makes sense that the props dept. would want to save money by buying cheap guns that no one would notice were not modern weapons.